Distribution, migration and changes of typical chemical preservatives on orange during storage and processing

The role of food preservatives in shaping metabolic profile and chemical sensitivity of fungi - an extensive study on crucial mycological food contaminants from the genus Neosartorya (Aspergillus spp.)

Food preservatives are crucial in fruit production, but fungal resistance is a challenge. The main objective was to compare the sensitivity of Neosartorya spp. isolates to preservatives used in food security applications and to assess the role of metabolic properties in shaping Neosartorya spp. resistance. Sodium metabisulfite, potassium sorbate, sodium bisulfite and sorbic acid showed inhibitory effects, with sodium metabisulfite the most effective. Tested metabolic profiles included fungal growth intensity and utilization of amines and amides, amino acids, polymers, carbohydrates and carboxylic acids. Significant decreases in the utilization of all tested organic compound guilds were observed after fungal exposure to food preservatives compared to the control. Although the current investigation was limited in the number of predominately carbohydrate substrates and the breadth of metabolic responses, extensive sensitivity panels are logical step in establishing a course of action against spoilage agents in food production being important approach for innovative food chemistry.

Dissipation behavior and risk assessment of imidacloprid and its metabolites in apple from field to products

Pesticides play vital roles in controlling pests and boosting crop yields. Imidacloprid is widely used all over the world and may form in agricultural products. The presence of pesticide residues in apples raises serious health concerns. Understanding the residual fate of imidacloprid is critical for food safety and human health. In this study, the dissipation behavior, metabolism, household processing and risk assessment of imidacloprid and its metabolites in apple were investigated from filed to products. Field experiment results suggested that the half-lives of imidacloprid at 5 times the recommended dosage was 1.5 times that of the standard dosage. And the final residues of imidacloprid were less than the established maximum residue limits (MRLs). Clarification and simmering had little effect on the reduction the residues of imidacloprid and its metabolites. The calculated processing factors were lower than 1 for imidacloprid and its metabolites, implying that the residual ratios of imidacloprid and its metabolites in each steps of the food processing were reduced. The risk quotients were <1 for all Chinese people, indicating that acceptable risks associated with dietary exposure to imidacloprid in apple. However, the higher risks were observed in young people than adults, and females faced higher risks than males. Given high residue levels in pomace, imidacloprid and its metabolites should be further studied in commercial byproducts.

Effects of storage and processing on the residual distribution and behavior of five preservatives and their metabolites in pomegranate

Pomegranate are often treated with preservatives during storage. This study investigated the effects of storage and food processing on the residual behavior of the five commonly used preservatives (prochloraz, thiophanate-methyl, pyrimethanil, imazalil, and difenoconazole) and their metabolites in pomegranate and its products. The LOQs for all target compounds were 0.001 mg kg-1. The residue levels of five preservatives in the calyx was highest, followed by the peel, stalk, septum, umbilicus, and seed. For the migration ability, the five preservatives from pomegranate peel to seed was negatively correlated with their octanol/water partition coefficients. The processing factors of each procedures of juice, wine, vinegar, and pectin processing were <1. Nevertheless, the PF values in drying peel during the overall process ranged from 1.26 to 4.09. Hence, it is worth noting that consumption of pomegranate essential oil and drying peel may pose a potential risk to the health of consumers.

Occurrence, distribution, and translocation of legacy and current-use pesticides in pomelo orchards in South China

Pomelo (Citrus grandis) is a highly popular and juicy member of the citrus family. However, little is known regarding the occurrence and distribution of pesticides in pomelo. In this study, we determined the levels of legacy (n = 25) and current-use pesticides (n = 2) in all parts of pomelo (i.e., epicarp, mesocarp, endocarp, pulp, and seed) and paired soil and leaf samples collected from two pomelo orchards in South China. At least one target pesticide was detected in the pomelo fruit, soil, and leaf samples, indicating that these pesticides were ubiquitous. The spatial distribution of the total concentration of pesticides in the pomelo parts was in the order of epicarp (216 ng/g) > mesocarp (9.50 ng/g) > endocarp (4.40 ng/g) > seed (3.80 ng/g) > pulp (1.10 ng/g), revealing different spatial distributions in pomelo. Principal component analysis was performed based on the concentrations of the target pesticides in the pulp and paired samples of epicarp, leaf, topsoil, and deep soil to examine the translocation pathway of the pesticides in pomelo. Close correlations were found among the target pesticides, and the pesticides in the pulp were mainly transferred from the epicarp, topsoil, or deep soil. We also explored the factors that affected such transport and found that the main translocation pathway of the non-systemic pesticide (i.e., buprofezin) into the pulp was the epicarp, whereas the systemic pesticide (i.e., pyriproxyfen) was mainly derived from the soil. The cumulative chronic dietary risks of all the pesticides resulting from pomelo consumption were much lower than the acceptable daily intake values for the general population. However, the prolonged risk of exposure to these pesticides should not be underestimated. The potential health risks posed by legacy and current-use pesticides, which are widely and frequently utilized, should be given increased attention.

Simultaneous determination of spiropidion and its five major metabolites in sweet orange fruit and various processing by-products using ultra-high performance liquid chromatography-tandem mass spectrometry

The present work reported the application of an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous analysis of spiropidion and its five major metabolites in sweet orange fruit and by-products throughout the whole industrial juicing process of the orange fruit. The reversed-dispersive solid phase extraction (r-DSPE) with multi-walled carbon nanotubes (MWCNTs) was employed for the extraction and purification. The established method was validated and satisfactory parameters (linearity, trueness, precision, sensitivity, matrix effect and stability) were obtained. And then, the field trial of spiropidion on sweet oranges has been conducted and the effect of commercial juicing processing on the residue of spiropidion and its metabolites was further investigated. The various processing factors (PFs) for washing, juicing, sterilization, concentrating and essential oil collecting were also determined. The final results indicated that washing processing reduced residues by 18.4%; the juicing step allowed a significant decrease of the spiropidion residue by 34.2-70.8%, with PFs value in the range of 0.290-0.658. However, high level of residual spiropidion (ranging from 4.016 to 4.205 mg/kg) was detected in orange essential oil, with PFs value of 17.157. All the above results demonstrated the efficiency of the established method in the routine control analysis of spiropidion residues in sweet orange fruits and their by-products, and will facilitate the further intensive research on its spatial distribution, transfer and degradation during the different processing procedures of the sweet orange fruits.